SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0a3fd22403b75fa339ff318f8c1ecf31fb700b274ee3db06d73b999ca82845' 
  AND token = 'Xcg5GMJXzH/V+CqYSVRdJLXNBhtVEOSrxAqDphMimIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}